Baja Adveture Book.
I don't have my map but it was going up the road parallel to the Sea of Cortez, not the Pacific side. It was far north down a dirt road
Don't head down there without joining Baja Adventure Club. You can get car insurance, fishing license, and travel card before you leave the USA. It's just a fantastic resource with newsletters and a great bookstore.
I used to work on a ship, when it pulled into San Diego for shipyard, I would take off for 4-6 weeks. I kept my RV in Chula Vista. I would go to Costco, load up groceries and exchange dollars to Pesos. Then it was head south. I would bypass Tijuana, spend a night in Ensenada, clear the military check point south of Ensenada, and I was in the real Baja.
When are you thinking of going, I may have some books.